1. Field of the Invention
The present invention relates generally to methods and apparatus for treating pavement, such as, for example, concrete and asphalt saws.
2. Related Art
Concrete and asphalt saws are typically used to cut joints for expansion and contraction of such materials in freeway pavement, aircraft runways, and other pavement surfaces. Typical saws are marketed under different brand names and include a diamond blade of different diameters according to the thickness of the pavement to be cut, such as 12, 14, 16, or 24-inch blades, etc., driven by an internal combustion engine. The engine typically includes a dry air filter and/or an oil bath air filter for filtering incoming air prior to mixing for combustion in the engine. The engine is also used to drive a traction mechanism at the rear of the saw for advancing the saw along the pavement. A belt takes power from a pulley driven by the internal combustion engine for powering a transmission box to step down the revolutions per minute (rpm) of the engine to a suitable rate for driving the traction wheels of the saw.
The saw blade includes a semi-circular blade cover for protecting the blade during operation and for preventing injury while the blade is rotating. The blade cover also serves to contain cooling water sprayed onto the blade so that the cooling water drops onto the pavement. The blade guard is substantially circular around the blade. The blade cover is substantially fixed relative to the blade and saw.
The saw also includes a structural support frame for supporting all of the components and for mounting the wheels to the saw. The frame supports the engine, the shaft for driving the saw blade, the traction transmission and the pulleys for powering the traction transmission from the engine, among other elements.
In operation, the saw is started and positioned in alignment with the desired cutting path, and lowered into engagement with the pavement while at the same time turning on the coolant spray to the blade. An additional vehicle is located nearby for supplying water for cooling the blade through a suitable hose. As cutting continues, the water and resulting slurry from the abraded pavement spreads across the pavement, possibly filling previously cut joints. Sand blasting or water blasting has to be used to clean joints filled with such slurries to allow the contraction and expansion work. This procedure contributes to add more unwanted materials that cover the surface of the pavement and will fly away with the traffic or wind, polluting the environment. For environmental and other reasons, operators have begun vacuuming the water/slag slurry using a vacuum truck following along behind the saw to remove the slurry while the slag is still wet. However, such secondary vacuum vehicles require a substantial capital investment, are inefficient and only marginally clean the water and slag from the pavement.
There is a need for a more efficient and practical saw which more effectively contains the water and slag flow from the saw, and a more efficient and effective water and slag removal method and apparatus.